Heretofore, in order to test electric cord-sets, it has been necessary after the cord-set has been completed and removed from the molding machine, to place the male plug and female receptacle in special fixtures which closely embrace the outer surfaces thereof and which establish electrical connections with the contacts of the plug and receptacle. This, of course, required additional time and labor, which is eliminated by conducting the tests during the molding operation. Also, the electrical test may be carried out before the molding compound is injected and, if the test is negative, the parts may be removed and repaired, which could not be done after molding.